The candidate for this Mentored Career Development Award has a PhD in cognitive psychology and neuroscience with extensive training in the cognitive/neural mechanisms of stress, emotion, and mindfulness. This proposal is designed to facilitate the candidate's pathway to independence by providing training and mentorship in clinical assessment, and two new methodologies: eye-tracking and crowd-sourced online ?big data,? while also refining the candidate's neuroimaging skills. This training is essential to achieving the candidate's long-term goal of an independent career in translational clinical research investigating the predictors and correlates of posttraumatic neuropsychiatric sequelae, including pathological dissociation. Pathological dissociative symptoms in psychiatric populations are common, debilitating, and costly at both the personal and societal level; however, their biological mechanisms are largely unknown. Phenomenologically, dissociation encompasses a range of symptoms and occurs transdiagnostically. Traumatized individuals with dissociative symptoms typically have co-occurring psychiatric conditions, high rates of suicidality, and are disproportionate treatment utilizers. We propose that a novel way to measure dissociation is through the cognitive and neural processes associated with one's physical self (e.g., face) and psychological self (e.g., personality traits). A major goal of this proposal is to establish a new transdiagnostic, objective measure of dissociation by quantifying these self-related behavioral and biological correlates. Foundational research has documented differential patterns of brain activation in those with high vs. low levels of dissociative symptoms. These studies, however, have been limited in scope: 1) cross-diagnostic mechanisms have not been explored, 2) they have largely focused on a single paradigm, 3) they have targeted dissociative symptoms of detachment from the body and environment (depersonalization/derealization), which do not cover the wide range of documented dissociative symptoms. To address these limitations, we propose to examine the behavioral and biological correlates of face perception, self-face processing, and personality trait-based self processing in a transdiagnostic sample of individuals who report dissociative symptoms using neuroimaging, eye-tracking, and online big data collection techniques. Successful completion of these Aims will provide a much-needed dataset to further underpin biological theories of dissociation and will inform potential neural circuits to target for treatment. This research and training will occur at McLean Hospital, a Harvard Medical School-affiliated psychiatric hospital. McLean is a world leader in the treatment and research of mental illness, and in training generations of clinicians and scientists. It maintains the largest program of research in neuroscience and psychiatry of any private psychiatric hospital in the US. This facility and the greater Boston area offer a phenomenal set of resources to maximize the training and scientific potential afforded by this Career Development Award.